What is wrong with this loop.

for k=n:n-2,
    for i=n-1:1
        m=A(i,k)/A(k,k)
        for j=n:1
            A(i,j)=A(i,j)-A(k,j)*m
        end
        b(i)=b(i)-b(k)*m
    end
end

I am trying to write a for loop code for Guess Jordan Elimination, where n=length(b) A and b are both matrices of a system of equations.

I think the problem is with k because the value of k in the workspace is []

[per isakson]

See

• Debug a MATLAB Program
• for loop to repeat specified number of times

[KSSV]

YOu have not specified all the variables and you have not specified what error you face.

Answer 1

[Jos (10584)]

To have a for-loop iterate backwards you have to specify the increment

for k=1:10 % forward
...
end

for k = 10:-1:1 % backward
...
end

[Fatimah Alghazal]

I did what you said and it works..

Thanks,

This is the correct code.

 for k=n:-1:n-2,
    for i=(k-1):-1:1
          m=A(i,k)/A(k,k)
          for j=(k):-1:1
             A(i,j)=A(i,j)-A(k,j)*m
          end
        b(i)=b(i)-b(k)*m
    end
end